In this manuscript, we report the discovery of the substituted 2-trifluoromethyl-2H- benzopyran-3-carboxylic acids as a novel series of potent and selective cyclooxygenase-2 (COX-2) inhibitors. We provide the structure–activity relationships, optimization of design, testing criteria, and human half-life data. The challenge of a surprisingly long half-life (t1/2= 360h) of the first clinical candidate 1 and human t1/2 had been difficult to predict based on ...